What is Anti Mullerian Hormone?
It is also known as Mullerian Inhibiting Factor (MIF), or Mullerian Inhibiting Hormone (MIH), or Malaria Inhibiting Substance (MIS). Anti Mullerian hormone is a protein that is important for the development of the reproductive tract in the male foetus. It is produced by reproductive tissues, before birth, by testes in males and ovaries in females. The role of AMH and the amount normally present varies upon sex and age. The AMH plays a vital part in sexual differentiation in the foetus.
Role of AMH
Before birth, AMH is made in the foetus testis and ovary. Around the 7th week after the conception of the foetus has both Mullerian (female) and Wolffian (male) ducts, which can develop either into the male or female reproductive system. If the foetus has XY or male chromosomes, the testes will produce AMH and the Mullerian ducts will disappear. If the foetus has XX or female chromosomes a lack of testosterone will cause the Wolffian duct to vanish and the Mullerian duct will develop into a female reproductive system.
AMH has a role in puberty and it helps in the early development of follicles. AMH levels can be measured to determine how many follicles women have in their ovaries.
Significance of AMH
If a sufficient amount of AMH is not available or absent during the process of development of the foetus, then both male and female organs may develop.
AMH may be more produced in some ovarian tumours and thus tests can be used to identify tumors in the ovaries.
High AMH levels are also associated with polycystic ovary syndrome PCOS. The excess follicle in PCOS results in the production of a large amount of AMH.
The level of AMH is useful in identifying the egg reserve and chances of conceiving in females.
AMH is no longer produced when follicles degenerate or approach menopause. The level of AMH is used to identify the fertility status or menopause in females.
AMH also regulates the cyclical action of follicle stimulating hormone (FSH) and luteinizing hormone (LH).
Fate of AMH in Boys and Girls
Early in the development of a boy, AMH is produced by the testes which inhibit the development of female reproductive organs and thereby promote the development of male reproductive organs. In boys the level of AMH remains high until puberty after which it begins to decrease.
Whereas in girls low levels of AMH is produced initially which allows the development of female reproductive structures. The level of AMH is low until puberty but as the ovaries begin to produce eggs and follicles, the developing follicles produce more AMH and the levels increase. over the lifetime, as the reproductive phase begins to halt, there is a decline in the AMH level after which it becomes undetectable.
FAQs on Anti Mullerian Hormone
1. What exactly is Anti-Müllerian Hormone (AMH)?
Anti-Müllerian Hormone, or AMH, is a protein hormone that plays a crucial role in the sexual development of a fetus before birth. In women, it is also a very important indicator of ovarian reserve, which refers to the quantity of eggs remaining in the ovaries.
2. Where is AMH produced in males and females?
AMH is produced in different cells depending on an individual's sex:
- In males, it is secreted by the Sertoli cells located in the testes, beginning in the fetal stage.
- In females, it is produced by the granulosa cells of the small, developing follicles in the ovaries.
3. What is the main function of AMH in a developing male fetus?
In a male fetus, the primary job of AMH is to ensure correct sexual differentiation. It signals the breakdown of the Müllerian ducts, which are primitive structures that would otherwise develop into female reproductive organs like the uterus and fallopian tubes. This action clears the way for the male reproductive system to form.
4. What does an AMH blood test help doctors understand?
An AMH blood test is primarily used to evaluate a woman's ovarian reserve, or her remaining egg supply. The results help doctors estimate fertility potential, predict a woman's response to IVF treatments, and aid in the diagnosis of conditions like Polycystic Ovary Syndrome (PCOS).
5. What is considered a normal AMH level for a woman?
AMH levels naturally vary with age. However, a level between 1.0 ng/mL and 3.0 ng/mL is generally considered to reflect a normal ovarian reserve for women of reproductive age. Levels below this may indicate a diminished egg supply, while significantly higher levels can be associated with PCOS.
6. Why do AMH levels naturally get lower as a woman ages?
A woman is born with her entire lifetime supply of eggs, which are stored in tiny sacs called follicles. These follicles are responsible for producing AMH. As a woman gets older, the number of these follicles steadily declines through ovulation and natural processes. With fewer follicles available, less AMH is produced, causing the hormone level in the blood to naturally decrease over time.
7. How are unusually high AMH levels connected to PCOS?
Polycystic Ovary Syndrome (PCOS) is a condition often characterized by an excess number of small, undeveloped follicles in the ovaries. Since each of these follicles produces a small amount of AMH, the large quantity of follicles results in a much higher total AMH level in the bloodstream. This is why a very high AMH level is a key diagnostic marker for PCOS.
8. What happens if a male fetus fails to produce enough AMH?
If a male fetus has an AMH deficiency or if the body's tissues cannot respond to the hormone, the Müllerian ducts may not fully degenerate. This can lead to a rare condition where a male is born with internal female structures, such as a rudimentary uterus and fallopian tubes, alongside his normal male reproductive organs.
9. Is it possible to improve low AMH levels with lifestyle changes?
Currently, no diet or lifestyle change can create new eggs or significantly increase your AMH level, as it primarily reflects your egg count. However, focusing on a healthy lifestyle can improve egg quality and overall reproductive function, which is often more critical for achieving pregnancy than the AMH value alone.
10. How is AMH different from FSH when checking fertility?
Both AMH and FSH (Follicle-Stimulating Hormone) are important fertility hormones, but they provide different information:
- AMH measures the size of your remaining egg pool (quantity) and its level is relatively stable throughout the month.
- FSH stimulates follicle growth and its levels can fluctuate. A high FSH level can mean the brain is working extra hard to stimulate the ovaries, suggesting a lower reserve (quality and quantity).
